In determining whether a nonvested property interest or a power of appointment is valid under this article, the possibility that a child will be born to an individual after the individual’s death is disregarded.

(a) If, in measuring a period from the creation of a trust or other property arrangement, language in a governing instrument (1) seeks to disallow the vesting or termination of any interest or trust beyond, (2) seeks to postpone the vesting or termination of any interest or trust until, or (3) seeks to operate in effect in any similar fashion upon, the later of (A) the expiration of a period of time not exceeding 21 years after the death of the survivor of specified lives in being at the creation of the trust or other property arrangement or (B) the expiration of a period of time that exceeds or might exceed 21 years after the death of the survivor of lives in being at the creation of the trust or other property arrangement, that language is inoperative to the extent it produces a period that exceeds 21 years after the death of the survivor of the specified lives.

(b) Notwithstanding Section 21202, this section applies only to governing instruments, including instruments exercising powers of appointment, executed on or after January 1, 1992.